1. Field of the Invention
The subject of the invention is a method for determining parameters of a signal of OFDM type in a receiver comprising a tuner and a demodulator. The invention applies in particular within the framework of an over-the-air/terrestrial broadcast digital television system.
2. Related Art
In a terrestrial digital television receiver, in particular of DVB-T type, the circuits of the input stage must, for a given reception frequency, determine a certain number of parameters of the incoming signal. Among these parameters are, in particular:                the spectral inversion (or non-inversion),        the number of carriers in a COFDM symbol,        the duration of the guard interval between symbols, and        the frequency shift (“offset” used by the programme broadcasters to distance the digital channels from adjacent analogue carriers).        
According to the DVB-T standard, the number of possible values of each of these parameters are respectfully two, four and three. The receiver must thus test a maximum of 48 combinations of parameters, this corresponding on average to a success after 24 tries.